A conventional liquid crystal display apparatus causes the following problem. Specifically, in a case where, after a fixed pattern, in which a black display includes white square displays as illustrated in FIG. 15 (a), is displayed for a long time, it is changed into another display, for example, an entire half tone display, retentions occur at edge parts of the white square displays as burnings as illustrated in FIG. 15 (b). This allows a degradation in display quality. Note that FIG. 15 (b) shows an initial stage at which changing of displays are carried out and so a burning emerges only on one side of each of the white squares. After elapse of a long period of time, burnings emerge on four sides of the white squares.
To deal with this burning problem, for example, patent document 1 discloses an arrangement in which a counter electrode electric potential is adjusted to be a pixel electrode center electric potential (an electric potential of a center part of a pixel electrode) as illustrated in FIG. 16. Namely, a voltage having the positive polarity and a voltage having the negative polarity are alternately applied to a pixel between a counter electrode and a pixel electrode. As such, the voltage having the positive polarity and the voltage having the negative polarity, which have an identical effective voltage for an identical tone value, are applied to the pixel between the counter electrode and the pixel electrode, and so become symmetric with respect to the counter electrode voltage. This is carried out for all of the tones that can be displayed.
For example, patent document 2 discloses another conventional arrangement in which a direct-current component is removed to deal with the burning problem.    Patent Document 1: Japanese Publication for Unexamined Patent Application, Tokukaihei, No. 5-165431 (date of publication: Jul. 2, 1993)    Patent Document 2: Japanese Publication for Unexamined Patent Application, To kukai, No. 2002-251170 (date of publication: Sep. 6, 2002)
However, the conventional liquid crystal display apparatus and methods for driving the same are only for overcoming the problem of a plane burning, and still have a problem that an edge burning which would occur when a display of a fixed pattern, after having been displayed for a long time, is changed into a half tone display.
The present invention is made in view of the problem and an object of the present invention is to provide a liquid crystal display apparatus and a method for driving the same which can prevent an edge burning which would occur when the display of a fixed pattern, after having been displayed for a long time, is changed into a half tone image.